Tanisha Luster was arrested on Saturday in Nashville, after she pepper sprayed her ex-girlfriend’s new girlfriend, after finding them stopped at a red light. Get our your notepads and pay attention – Tanisha use to date Keisha. Since they broke up, Keisha is now dating a girl named Kiara. On Saturday night, the new couple (Keisha & Kiara) were at a stoplight near Metro Center. Keisha was driving, and Kiara was in the passenger seat, with her window rolled down. As they were waiting for the light to turn green,…